Method and apparatus for heat processing glass batch materials

ABSTRACT

An apparatus and method are disclosed for processing glass-making materials under oxidizing conditions, and for processing materials, such as hazardous or toxic wastes, or smelting under reducing conditions. As a glass-making apparatus the invention includes a cyclone melt reactor for forming a liquid glass melt and a combustion preheater for receiving the glass-making materials and combusting the fuel and oxidant therein to heat the glass batch materials to a temperature at least equal to the melt temperature of the glass batch material. The combustion preheater has an outlet connected to the glass melt reactor, and at least one inlet is provided into the combustion preheater for introducing oxidizing materials and for creating a well-stirred region within the combustion preheater means. Supplemental heat can be provided by introducing a heated transfer gas into the combustion preheater, and a fuel gasifier can be provided for producing a fuel gas before the fuel gas is injected into the combustion preheater. 
     For processing materials under reducing conditions, the cyclone melt reactor is connected to a preheater/reducing chamber and preheated reducing gas is introudced into the reducing chamber in such a manner that a well-stirred region is created within the reducing chamber. Heated transfer gas from a supplemental heat source and reducing gas from a fuel gasifier can also be introduced into the reducing chamber.

FIELD OF THE INVENTION

This invention relates to glass production and in particular relates topreheating of glass batch materials in a combustion preheater prior torapidly melting the glass batch materials in a cyclone melting chamber.The apparatus and process are also applicable to the melting of othermaterials and to treatment of hazardous, toxic or infectious waste

BACKGROUND OF THE INVENTION

Many attempts have been made to improve the efficiency of glass meltingfurnaces over the past 50-75 years. To date, however, very few newmelting concepts have been adopted by the glass industry.

These attempts to increase glass melting/glass production efficiencyhave included, in particular, glass batch material preheating techniquesused in conjunction with different glass melting methods to increase therate at which the glass melting process occurs. Batch materialpreheating processes which have been tried include: using moving bedreactors, raining bed reactors, fluidized bed reactors, counter-flowsuspension reactors, plug flow type suspension reactors and dumpcombustors with flame holders to preheat the batch material prior tomelting. In addition to attempts to increase efficiency by preheatingthe batch material, enhanced or improved glass melting processes haveincluded methods utilizing submerged combustion, direct heating ofmoving batch surfaces, melting over bodies of revolution or othersurfaces, melting in rotating cylinders and melting in cyclone typereactors.

Of particular interest with respect to the present invention is glassmelting in cyclone type reactors. Previously, patents relating tocyclone type reactors have issued to Ferguson, U.S. Pat. No. 2,006,947;Jack, et al., U.S. Pat. No. 3,077,094; Boivent, U.S. Pat. Nos. 3,443,921and 3,510,289; Ito, U.S. Pat. No. 3,748,113; Niefyodon et al., U.S.S.R.Pat. No. 0708129 and Hnat, U.S. Pat. No. 4,535,997 and 4,544,394. Eachof these patents discloses the use of a cyclone reactor for the finalglass melting step and includes combustion or other forms of heataddition, such as penetrating burners within the cyclone meltingchamber, in order to elevate the batch materials to the requisite glassmelting temperature.

The previous patents to Hnat pay particular attention to the use ofvarious types of cyclone designs as well as the use of specific,separate batch injection locations as means of controlling the losses ofhigher volatile mineral matter, such as soda ash and borox. Otherwise,the prior cyclone melting approaches for improving glass productionefficiency have generally not considered means of limiting the losses ofvolatile mineral matter such as fluxing agents, viscosity controlagents, fining agents or reducing agents prior to melting in the cyclonereactor. In particular, methods of controlling the time-temperaturehistory of the volatile mineral matter in the suspension preheatingsteps have not been previously developed.

Prior glass melting methods utilizing ash containing fuels, such ascoal, have not been successful because of the poor economics associatedwith coal gasification processes or, as in the case of direct coalfiring, because the ash contamination in the glass has been unacceptablefrom the standpoint of quality control. Even though typical coal asheshave constituent species which are identical to those found incommercial glasses, the concentration distribution of the individualconstituent species is substantially different. The iron oxideconcentrations in coal ashes are typically much higher thanconcentrations found in common commercial glasses. Coal ashes typicallyhave iron oxide concentrations in the range of 10-20%, whereas mostglass compositions have iron oxide concentrations of less than 0.1-0.2%,and iron oxide concentrations for flint container glass must begenerally lower than 0.02% if acceptable coloration is to be achieved.The quality control requirements for amber and green bottle glass areless restrictive, but the quality control requirements still generallyrequire that iron oxide concentrations be less than 0.1 and 0.3%,respectively.

With insulation fiberglass, higher levels of iron oxide are tolerable,with iron oxide concentrations of 1-2% being acceptable. Iron oxidelevels higher than 1-2% generally lead to a degradation of theinsulating value and can cause material compatibility problems withexisting fiberizers. Mineral wools, which are often made from blastfurnace slags, have iron oxide concentrations in the same range as coalash; therefore, the production of this product is not very sensitive tocoal ash contamination. The efficiency of mineral wool production,however, is substantially less than the production of insulationfiberglass because of the previously mentioned material compatibilityproblems with high efficiency fiberizers.

Because of the ash contamination problems, and in particular the problemof iron oxide contamination, very few prior glass melting inventionshave considered or succeeded in direct firing using coal or other fuelscontaining substantial amounts of ash as a fuel. In fact, direct firingof conventional open hearth-type furnaces with pulverized coal has beenunsuccessful because of ash carry over into the regenerators.Furthermore, refractory corrosion and blockage problems have occurred,as well as the formation of stones and cords within the melt, because ofslagging within the furnace chamber.

The ability to fire the glass melting systems with fuels subject to ashcontamination is now an important consideration in light of the fuelefficiency and the high temperature heating that can be obtained, butuse of these fuels has not, heretofore, been successfully achieved. Inthe recent prior art of Demarest et al., U.S. Pat. No. 4,634,461, thepossibility of using pulverized coal in a rapid glass melting process istaught; however, in that patent the coal ash is actually incorporatedinto the glass batch materials and the final glass product with no meansof controlling the level of ash contamination.

OBJECTS OF THE INVENTION

With this background in mind, it is an object of the invention toprovide an apparatus for the formation of a glass melt from glass batchmaterials, fuel and oxidant under oxidizing conditions wherein the glassforming materials are preheated in a suspension chamber to a temperatureabove the melt temperature of the batch materials prior to introductioninto a cyclone melter where separation and dispersion of the batchmaterials occurs on the melter wall and a liquid glass melt is obtained.

It is a further object of the invention to provide a preheatingsuspension chamber wherein the batch materials, fuel and oxidant aremixed in a well-stirred region.

It is a further object of the invention to provide additional heat intothe preheating chamber by introducing a heated transfer gas thereinto.

It is another object of the invention to provide a glass meltingapparatus capable of using different fuels, such as coal, gas, oil andslurry fuels.

It is another object of the invention to provide a glass meltingapparatus capable of using ash-bearing fuel by the addition of agasifier for gasifying the fuel prior to introduction of the fuel intothe preheater chamber.

It is yet another object of the invention to provide a glass meltingapparatus wherein the gasifier which prepares the fuel for the preheateris a slagging gasifier which removes solid contaminant particles fromthe fuel.

It is an object of the invention to provide a glass melting apparatuswherein glass batch materials having different melting points can beintroduced into the preheating chamber at different locations.

It is an object of the invention to provide a glass melting methodwherein glass batch material, fuel and oxidant are introduced into andcombusted within a preheating chamber to a temperature higher than themelting point of said batch materials before being introduced into acyclone glass melter.

It is another object of the invention to provide a glass melting methodwherein the glass batch material, fuel and oxidant are mixed togetherand combusted in a well-stirred, turbulent region within a preheatingchamber.

It is a further object of the invention to provide a glass meltingmethod wherein additional, heated transfer gas can be introduced into apreheating chamber along with glass batch material, fuel, and oxidant inorder to increase the temperature during combustion within thepreheater.

It is an object of the invention to provide a glass melting methodutilizing a preheating chamber and cyclone melting wherein fuelscontaining solids can be gasified in a slagging gasifier prior tointroduction into the preheating chamber.

It is a further object of the invention to provide a glass meltingmethod utilizing a preheating chamber and a cyclone melter wherein thetemperature within the preheating chamber can be adjusted.

It is another object of the invention to provide an apparatus and methodwhich can be utilized for processing materials under reducing conditionswherein the materials being treated are heated under reducing conditionsin a suspension reducing chamber before being introduced into a cyclonemelter.

It is yet another object of the invention to provide an apparatus andmethod for processing materials under reducing conditions utilizing areducing chamber and a cyclone melter wherein heat sources are providedfor heating reducing materials before introducing the reducing materialsinto the reducing chamber.

It is an object of the invention to provide an apparatus and method forprocessing materials under reducing conditions utilizing a reducingchamber and a cyclone melter wherein fuels containing solids can begasified in a slagging gasifier prior to being introduced into thereducing chamber.

SUMMARY OF THE INVENTION

In furtherance of these objects, an apparatus and method are disclosedfor processing glass-making materials selected from glass batchmaterials, fuel and oxidant under oxidizing conditions, and in addition,the apparatus can also be used for processing materials, such ashazardous or toxic wastes, or smelting under reducing conditions. As aglass-making apparatus the invention includes a cyclone melt reactor forforming a liquid glass melt and a combustion preheater for receiving theglass-making materials and combusting the fuel and oxidant therein toheat the glass batch materials to a temperature at least equal to themelt temperature of the glass batch material. The combustion preheaterhas an outlet connected to the glass melt reactor, and at least oneinlet is provided into the combustion preheater for introducingoxidizing materials and for creating a well-stirred region within thecombustion preheater means. A supplemental heat source can also beprovided to introduce a heated transfer gas into the combustionpreheater, and a fuel gasifier can be provided for producing a fuel gasbefore the fuel gas is injected into the combustion preheater.

As an apparatus and method for processing materials under reducingconditions, a cyclone melt reactor is connected to a preheater/reducingchamber and preheated reducing gas is introduced into the reducingchamber in such a manner that a well-stirred region is created withinthe reducing chamber. Heated transfer gas from a supplemental heatsource and reducing gas from a fuel gasifier can also be introduced intothe reducing chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and many of the attendant advantages of the instantinvention will be readily appreciated as the same become understood byreference to the following detailed description considered inconjunction with the accompanying drawings, wherein:

FIG. 1 is an isometric view of the glass melting apparatus of thepresent invention showing the major components of the preferredembodiment.

FIG. 2 is a diagrammatic cross-sectional view of an embodiment of thepresent invention which includes a counter-rotating vortex suspensionpreheater and a cyclone melter.

FIG. 3 is a sectional view of the counter-rotating vortex suspensionpreheater taken along the line 3--3 in FIG. 2 showing the opposed swirlorientation of the gas/air inlets.

FIG. 4 is a diagrammatic cross-sectional view of an embodiment of thepresent invention which includes an impinging jet vortex suspensionpreheater and a cyclone melter.

FIG. 5 is a diagrammatic cross-sectional view of an embodiment of thepresent invention which includes a cutaway view of a plasma torch on thehead end of a counter-rotating vortex suspension preheater.

FIG. 6 is a diagrammatic cross-sectional view of an embodiment of thepresent invention which includes a slagging cyclone gasifier connectedto a counter-rotating vortex suspension preheater.

FIG. 7 is a sectional view of the slagging cyclone gasifier taken alongthe line 7--7 in FIG. 6 showing the orientation of the batch injectioninlet and the hot raw gas exit.

FIG. 8 is a diagrammatic cross-sectional view of an embodiment of thepresent invention which includes a cutaway view of a plasma torchattached to a slagging cyclone gasifier.

FIG. 9 is a sectional view taken along the line 9-9 in FIG. 8 showingthe orientation of the plasma torch relative to the gasifier exitassembly.

FIG. 10 is an isometric view of an embodiment of the present inventionwhich includes plasma torches affixed to gas/air inlets of an impingingjet suspension preheater/reducing chamber.

FIG. 11 is a diagrammatic cross-sectional view of an embodiment of thepresent invention which includes cutaway views of plasma torches affixedto the gas/air inlets of a counter-rotating vortex suspensionpreheater/reducing chamber.

FIG. 12 is a sectional view of an embodiment of the present inventiontaken along the line 12-12 in FIG. 11.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The following detailed description of the preferred embodiment of theinvention is made primarily with reference to a glass melting operationunder oxidizing conditions for which the invention has been foundparticularly useful. However, essentially the same equipment used tomelt glass can also be used to melt pulverized frits, pulverized slagsor flyash. Flyash and slags typically have higher melting points thanglass frits, which are previously melted glass products, and thereforethe operating temperature of the preheater and melt chambers must beelevated to accommodate these higher melting point materials. The sameessential process steps are utilized in both operations. When meltingsingle component materials like flyash, the minimization of volatilelosses from the feed stock is not necessary unless fluxing agents areadded separately to the system in order to reduce the meltingtemperature of the feed stock materials.

The invention can also be used for the incineration and glassencapsulation of hazardous or toxic waste under oxidizing conditions.The application of the invention to treating toxic or hazardous wastesis in the incineration of contaminated soils or other waste whichcontain substantial amounts of inert mineral matter. The formation of aglass material from asbestos fibers is another example of theapplication of the invention. When used as a toxic waste incinerator,the device is operated above the slagging temperature of the mineralmatter residue or ash so that a molten material is formed. Depending onthe toxic waste being incinerated, pulverized glass cullet or otherglass forming ingredients can be added to the process to form a glassmatrix material which can be suitably formed and packaged for safe landfilling. For example, the formation of glass marbles or granular sizecullet with relatively small surface-to-volume ratio would be a suitableform for disposing of the glass-encapsulated material produced. Inasmuchas the invention requires that the feed stock used be pulverized, meansfor particle size reduction of the feed stock and transporting of thetoxic waste material to the heat processing unit must be provided.Materials which are sticky or not transportable by pneumatic means canbe transported to the heat processing unit in an oil or water slurry.When a transport oil slurry is used, the oil can be used as the fuel forthe incineration process. Because the process unit typically operates attemperatures in excess of 2600° F, any hydrocarbons within the toxicwaste will be driven off and burned in the suspension preheaterassembly, which will typically be operated with excess air toaccommodate the burning of hydrocarbons volatized during the suspensionpreheating of the toxic waste materials.

Referring in greater detail to the various figures of the drawingswherein like reference characters refer to like parts, the meltingapparatus of the present invention is generally shown in FIG. 1. Theprimary components of the apparatus of the invention include asuspension-type preheater chamber 100, a cyclone melting chamber 200 atthe discharge end of the preheater chamber 100, a cyclone exit assembly300 at the discharge end of the melting chamber 200, a slagging cyclonegasifier 400, a plasma torch gas preheater assembly 600 and agasifier/preheater interface assembly 500 joining the gasifier 400 andthe plasma torch assembly to the preheater chamber 100.

While FIG. 1 shows the interconnection of all of the above identifiedcomponents, the basic functional apparatus may comprise only thecylindrical type combustion preheater 100, the cyclone melting chamber200 and the cyclone exit assembly 300. This construction is shown inFIG. 2. As shown in FIG. 2, fuel 30 is introduced into the top or headend 102 of the preheater 100. The fuel 30 is introduced along with theglass batch material 10 through an injector assembly 104 which islocated at the head end 102 of the preheater 100 and which is coaxialwith the longitudinal axis of the preheater chamber 100.

The preheating step is very important to the invention. The wellstirred/plug flow suspension preheater 100 enhances the convective heattransfer to the particulate matter, while providing combustionstabilization when combustion occurs within the preheater vessel. Due tothe intense mixing, there is rapid heat release in the combustionprocesses which take place. By selecting the proper injection locationand velocity, the interaction of the particulate mineral matter with thewalls of the preheater can be either minimized or maximized. Axialinjection will tend to minimize interaction with the preheater wallwhile tangential injection tends to maximize the interaction with thereactor wall, particularly in the embodiments which utilize high levelsof swirl.

As shown in FIG. 3, preheated air or other suitable gaseous oxidizingmaterial 20a, 20b is introduced into the preheater 100 through two ormore inlet ports 106a, 106b. These gaseous oxidizing materials 20a, 20bare introduced in such a manner that they produce turbulent mixing ofthe injected fuel 30 with the oxidizing material 20a, 20b and the glassbatch material 10. The result is a mixture of fuel, oxidizer and glassbatch material in the upper region 108 of the preheater 100. Within thisupper region 108, the gasses present are well stirred or well mixed, butthe particulate matter (e.g., glass batch material) in this region 108is not necessarily well stirred or evenly distributed throughout thevolume of region 108.

When a counter-rotating preheater is used as shown in FIGS. 2 and 3, theinlet ports 106a, 106b are tangential to the vessel walls and are spacedat different levels. The jets are typically vertically spaced on theorder of 1/4 to 1 reactor vessel diameter apart. When an opposed orimpinging jet preheater is used as shown in FIG. 4, the inlet jet ports107a, 107b are at the same level and are preferably directed at anupward angle of approximately 45°, although the angles may range from30°-60°. The jet ports 107a, 107b of the opposed jet preheater aretypically positioned such that the issuing streams or jets impinge oneach other or on a third, preferably downwardly directed, stream issuingalong the centerline from the head end 102 of the chamber 100. Whileupwardly directed impinging jets are preferable, it is envisioned thatan embodiment is possible where the jets might be downwardly directed asfound in some coal gasifying devices.

The combustion of the fuel 30 and the oxidizing material 20a, 20b withinthe upper region 108 of the preheater 100 results in a high intensityheat release and further results in a rapid rate of heat transfer to theparticulate matter (e.g. the glass batch materials) suspended in the gaflow within this region. Burning within the preheater occurs via themixing and stirring of the fuel and oxidizer within the well-stirredregion of the reactor. The ignition occurs within the preheater with theaid of a pilot burner or conventional electrical ignition assembly. Inthe preferred embodiment, high temperature air preheat (>1200° F) willbe provided via a commercially available heat recuperator. In thesecases radiation from the preferable refractory lined reactor walls willgenerally establish auto ignition of the various fuel an oxidizermixtures to be used. Strong recirculation in the upper region 108 of thepreheater 100 is created by counter-rotating vortices or impinging jets,thus providing the primary means of flame stabilization within thepreheater. Without this strong recirculation of the combustion gases,flame extinguishment tends to occur due to the quenching of the flame bythe inert batch materials or other mineral matter within the preheaterassembly. This is particularly true of mineral matter, such aslimestone, which liberates substantial amounts of CO₂ upon heating. Whenlow heating value fuels are used, auxiliary gas injection, separateigniters or pilot burners can also be used as a means of providing flamestabilization within the preheater.

When the preheater 100 is a cylindrical type combustion chamber, theprimary flame and heat release occurs in the upper region 108 whichoccupies a chamber volume with a length to diameter ratio ofapproximately 0.5:1-1.5:1, and preferably 1:1. The strong mixing of thefuel and oxidizer within this region permits the effective combustion ofmany types of fuels, including gaseous, liquid, solid or liquid-solidslurry type fuels, in the presence of substantial amounts of pulverizedglass batch material which is essentially non-combustible in nature.

Slurry fuels, such as coal-water slurries or coal-oil slurries caneither be burned directly in the well-stirred/plug flow preheater 100 byutilizing suitable commercially available or modifiedinjection/atomization assemblies, or they can be first gasified in acyclone gasifier and the hot raw gas subsequently burned in thepreheater. The latter approach provides a means of separating out theash in the fuel so that contamination of the product by the coal ash isminimized.

Downstream of the upper region 108 within the preheater 00 is a lower orplug flow region 110 wherein a plug flow of gas and solid or liquidparticles is produced and wherein final combustion of the fuel 30 iscompleted. By plug flow it is meant that the gas recirculation patternshave abated and the primary direction of flow is parallel to thelongitudinal axis of the reactor. The effective length-to-diameter ratioof the plug flow region 110 is, again, approximately 0.5:1-1.5:1, andpreferably, 1:1. The gaseous materials, fuel 30 and oxidizers 20a, 20b,and the entrained glass batch materials 10 within this plug flow region110 are accelerated through a converging section 112 of the preheaterchamber 100. From the converging section 112, the gas and entrainedbatch materials are delivered without further combustion, but at anaverage temperature which exceeds the melting point of the glassproduct, into a cyclone-type melting chamber 200 wherein separate,dispersion, mixing and melting of the preheated batch materials occursalong the walls 202 thereof without further combustion of fuel.

It is the intention of the invention to heat the batch materials insuspension and to minimize liquid glass formation along the walls of thepreheater 100. However, when low melting point species are included aspart of the batch mixture, some liquid glass specie formation will occuralong the walls of the preheater by vapor phase condensation or byturbulent deposition. The amount of glass formation along the walls ofthe preheater relative to the amount of glass formation in the cyclonemelter should be relatively small (i.e., typically less than 10%).

The melted glass product 16 formed on the walls 202 of the cyclonemelting chamber 200 and hot gases 32 from the cyclone chamber exit thecyclone melting chamber 200 through the exhaust duct assembly 300 whichis preferably positioned tangential to the walls of the cyclone meltingchamber.

To produce the appropriate plug flow in the lower plug flow region 110of the counter-rotating preheater 100, it is necessary to correctlyproportion the momentum of the inlet streams 20a, 20b of the oxidizingmaterial. This proportioning can be achieved by adjusting the mass flowsand inlet velocities of the oxidizing streams 20a, 20b into thepreheater by suitable conventional control valves and by adjusting thedimensions of the inlet locations 106a, 106b. In a counter-rotatingvortex combustor, it has been found that equal momentum inlet jets donot necessarily lead to plug flow downstream of the well-stirred region108. Therefore, momentum adjustment of the individual streams must bemade in order to achieve the desired plug flow pattern in the lowerregion of the preheater. In the impinging jet reactor design, it isgenerally necessary that the jets of oxidizing material be of equalmomentum in order to achieve a well developed plug flow (i.e., minimalresidual swirl) in the lower region of the preheater.

If the gas flow patterns of the upper and lower regions are establishedproperly, then the time-temperature history of the injected glass batchmaterials leaving the preheater can be controlled by suitably adjustingthe batch material inlet location, the inlet direction, the velocity ofthe batch materials at the inlet and the particle size distributions ofthe individual batch materials. When it is not critical that theinteraction of the batch materials 10 with the preheater walls beminimized (e.g., during the melting of glass cullet or glass frit), itmay be acceptable to introduce these materials into the preheater alongwith the oxidizing materials through the inlet ports 106a, 106b. Forexample, as shown in FIG. 3, inlets 106', 106" may be provided into theinlet ports 106a, 106b. Inlet 106' may be used to inject additionalbatch materials 10 into the inlet ports for injection into the preheater100, and inlets 106" may be provided to inject additional fuel 30 intothe inlets. In this embodiment , the concentration of particulates inthe recirculation vortices will be greater, and the interaction of theparticulates with the walls of the preheater will be greater. If thematerials introduced readily melt and form along the reactor walls aliquid glass layer which is continuously removed, then the interactionof the particulate matter with the reactor walls is not a criticalmatter. However, the preferred method of batch material preheating is tominimize the amount of particulate interaction with the preheater walls.

It is also possible to provide separate injection of low melting pointbatch materials into the exit region 116 of the preheater 100 or intothe vicinity of the inlet 204 into the cyclone assembly 200. Such alocation is shown at the inlet 114 through the wall 118 of theconverging section 112.

Convective heat transfer to the glass batch materials suspended in thecombustion preheater 100 is the primary heat transfer mechanism.Radiation heat transfer plays a lesser role in this type of process thanin conventional open-hearth type furnaces. The average gas temperaturewithin the preheater 100 affects the ultimate preheat temperatureachieved by the batch materials passing therethrough. Therefore, thepreheater temperature is another control variable in this invention. Thetemperature of the preheater 100 is controlled by adjusting combustionstoichiometry, the level of oxidizer present, the level of oxygenenrichment and the type of fuel utilized. Combustion stoichiometry iscontrolled by adjusting the fuel/air ratio. This is done usingconventional fuel and air flow control techniques. The level of oxygenenrichment is adjusted by utilizing an outside oxygen source and usingconventional techniques for mixing and proportioning the amount of airand oxygen used in the process. As presented in this invention the airand oxygen are mixed prior to introduction into the preheater. Also,temperature may be controlled through the use of an auxiliary heatsource (as will be discussed hereinafter.)

In conventional open-hearth furnaces, auxiliary heat is oftentimes addedto the melting process by electrical boost. The usual means ofelectrical boosting incorporates the immersion of pairs of electrodesinto the glass melt within the furnace. In the present invention, plasmatorches 600 or electrical arc discharges can be used to augment thermalinput into the glass melting process. Plasma torches are well known inthe art and are devices for generating gas plasmas. A gas plasma is agas which has been highly ionized; that is, a large percentage of theelectrons have been stripped from the atoms of the gas thereby makingthe gas electrically conductive. The most common types of plasma torchesare either of the transferred arc type or the nontransferred arc type.In the transferred arc design, a plasma supporting gas is passed betweenan electrode (typically, the cathode) and material to be processed whichalso serves as an electrode (typically, the anode). Heat is transferredfrom the plasma to the processing material primarily by conduction. Inthe non-transferred arc device, the plasma supporting device is passedthrough the self-contained electrodes (cathode and anode) and heat istransferred to the plasma supporting gas, which in turn transfers heatto the processing materials by radiation and convection. In the presentinvention, the non-transferred plasma torch is the preferred design formost of the applications presently envisioned. Other types of plasmagenerators, such as electrodeless plasma generators which utilize timevarying magnetic fields, are also being utilized in laboratoryexperiments, but are not presently available on a commercial basis.

In the configuration shown in FIG. 5, a plasma torch 600 is mounted atthe head end 102 of a counter-rotating vortex preheater -00 along withinlets 120, 122 through which are deliVered the fuel 30 and batchmaterials 10, respectively, into the preheater 100. Thermal augmentationusing the plasma torch 600 is achieved by heating a heat transfer gas 40passing therethrough to a temperature higher than the average gastemperature within the preheater 100 and injecting the heated transfergas 40' into the preheater 100. The temperature of the injected transfergas 40' is higher than the temperature which could have existed withoutauxiliary heating. By mixing the heated transfer gas 40' with theinjected batch materials 10, fuel 30 and oxidizer flows 20a, 20b in thepreheater 100, a higher temperature gas-solids suspension is formed inthe upper region 108 of the preheater 100.

The heat transfer gas can be air, a fuel gas or an inert gas. In atypical application, the nature of the heat transfer gas (i.e.,oxidizer, fuel or inert) is taken into account in establishing theoverall combustion stoichiometry in the preheater. In applications whereit is desirable to maintain oxidizing conditions in the preheater, theheat transfer gas will generally be air. In applications where it isdesirable to maintain reducing conditions in the preheater, the heattransfer gas will typically be a reducing or a fuel gas.

The use a of plasma torch or the use of other sources capable ofproducing high heat, such as an electrical arc discharge, raises thecombustion preheater chamber temperature without increasing thecombustion air preheat temperature via a heat recuperator or the levelof oxygen enrichment. The use of heat recuperators to elevate thecombustion air temperature and oxygen enrichment are common means ofachieving high temperatures in combustion processes. The level of heatrecuperation and oxygen enrichment is often dictated by economicconsiderations. The achievement of high air preheat temperatures withrecuperators is often limited by materials of construction as well asother engineering considerations. Therefore, the use of plasmagenerators provides a means of increasing the reactor temperature byeither providing additional heat to the fuel gas or to the oxidizerwithout the need for additional heat recovery equipment or oxygenstorage/generation equipment. In the present invention, the plasmagenerator is not the primary heat source for the process, but is used asa process trim or an adjustment input. Thus, by using the plasma torch,the apparatus and method otherwise remain the same as discussed withrespect to the apparatus shown in FIG. 2.

In the embodiment of the invention shown in FIG. 6, a slagging gasifier400 is included to provide a high temperature fuel gas 403 for injectioninto the upper region 108 of the counter-rotating preheater 100. Theslagging gasifier 400 is closely linked to the preheater 100 in order tominimize the heat losses in the interconnecting duct work. Other typesof gasifiers can also be used, but generally they operate at lowertemperatures, are not as thermally efficient, and are more expensive.Therefore, the close-coupled slagging gasifier is a preferred gasifier,but is not the only possible fuel gas source for the process. The use ofa slagging cyclone gasifier 400 is also preferred since it is capable ofremoving a majority of any fuel ash in the form of molten slag 401.

In the cyclone gasifier 400, fuel 30 (typically pulverized coal) isintroduced at the head 406 of the gasifier through a suitable injectorassembly 408 (such as a commercially available coal injector).Additionally, it is preferable that preheated combustion air or otheroxidizing material 20 be introduced through an inlet 409 tangentially tothe inside of the cylindrical gasifier 400 in order to cause a strongswirling motion within the gasifier 400. The result of the swirlingmotion of the gases within the gasifier is the separation of most of thefuel ash from the coal to the walls of the gasifier in the form ofmolten slag 401. The slag is removed from the gasifier through asuitable slag trap 410. Typically a small amount of the coal ash (i.e.,less 30%) is not separated in the cyclone gasifier and is carried overwith the heated fuel gas 403 into the batch preheater 100.

The raw fuel gases 403 and any ash carryover exit the gasifier 400 intoa gasifier/preheater interface assembly 500 prior to introduction intothe preheater 100. The interface assembly 500 also contains inlets 502,504 for the injection of batch materials 10 into the hot raw gas 403.The mixing of the hot raw gas 403 and the batch materials 10 in theinterface assembly results in a heated gas-solids suspension 404 whichis introduced into the upper region 108 of the preheater 100. Thegas-solids mixture injects into the preheater through a duct or a nozzle506 located along the longitudinal axis of the preheater 100.

The interface assembly 500 is provided to minimize the wall heattransfer losses while providing a flow straightening mechanism for theswirling gases exiting the cyclone gasifier. The flow straightening isaccomplished by providing a tangential exit 505 which is co-current withthe direction of swirl. It is also a convenient location for theintroduction of batch materials 502, 504 as well as a possibleattachment point for a plasma torch (FIG. 8). In all cases, thepreferred introduction of batch materials is co-incindent with the exitduct of the interface assembly. The preheater 100 as shown in FIG. 6 andthe operation thereof are essentially the same as described for theembodiment shown in FIG. 2.

In addition to the embodiment of the invention shown in FIG. 6, whereina slagging gasifier 400 is provided, as shown in FIG. 8, a plasma torch600 may be connected to the interface assembly 500 connecting theslagging gasifier 400 to the combustion preheater 100. Electric arcdischarges could also be used to electrically boost the process;however, they are not as compact and convenient to interface with theprocess unit and are more cumbersome to incorporate into the design. Theplasma torch 600 can be used to provide thermal energy to a transfer gas40 directed therethrough. The heated transfer gas 40' (i.e., plasmasupporting gas) will typically be heated to temperatures in the range of7000° F to 17,000° F. Air preheated by a recuperator is typicallylimited to a temperature of 1200° F to 2200° F. The ultimate temperaturewhich can be achieved within the process unit is dictated primarily byconsiderations of survivability of the wall containment materials. Theheated transfer gas 40' heated by the plasma torch is introduced intothe cylindrical interface assembly 500 through an inlet 602 which ispreferably positioned tangential to the interior of the interfaceassembly (FIG. 9). Mixing of the gases 40', 403 occurs within theinterface along with the batch materials 10 to form a higher temperaturegas-solid suspension 404'. This gas-solid suspension 404' has atemperature higher than would be possible without the auxiliary heatingsource/plasma torch 600.

The remaining elements of the embodiment shown in FIG. 8 are the same aspreviously described.

The method and apparatus discussed in association with FIGS. 1-9 havebeen presented primarily with the consideration that the apparatus wouldbe used to melt glass batch or other mineral matter under slightlysub-stoichiometric or oxidizing conditions. By oxidizing conditions, itis meant that there is more oxygen than is needed for completecombustion of the fuel. Therefore oxygen will be one of the species inthe combustion products and there will be little carbon monoxide orhydrogen in the combustion products Reducing conditions in contrast,means that there is insufficient oxygen to complete combustion. Underreducing conditions, the percentages of hydrogen and carbonmonoxide aresubstantially higher, and there is essentially no free oxygen available.

The atmosphere in which the glass is melted can have effect on thechemistry of the glass melting process. For example, the iron oxidere-dox states are influenced by the combustion stoichiometry which inturn can influence the color of the glass produced. In someapplications, for example the smelting of metal-containing ores ormetal-containing waste materials (e.g. waste dust from electric arcfurnaces), it is necessary to operate the melting process under highlyreducing conditions if significant levels of reduction are to beachieved. In the embodiments shown in FIGS. 10-12, apparatuses are shownwhich allow the reduction of metal-containing mineral matter or wastematter. Herein, as elsewhere, like components are presented by likenumerals

One purpose of the reduction embodiment is to economically produce ironor other metals from ores or metal-containing waste. The smelting ofpulverized ores and the recovery of metals from electric arc furnacedust are examples of suitable applications of this technology. In thepresent invention, plasma torches 600a-c are used as a means ofproviding supplemental enthalpy input to the reduction process. Theprimary energy source for the reduction step comes, however, from thehigh temperature gasification of coal. Previous attempts solelyutilizing electrically driven plasma technology have not been successfulbecause of the unfavorable economics of these processes

When the present invention is utilized for the reduction of ores orother metal oxide containing materials, the suspension preheatingchamber 100 and the cyclone melter 200 must be operated under veryreducing conditions and at high temperatures. The preferred embodimentof a reduction process consists of a slagging cyclone gasifier 400 whichprovides a hot reducing gas to the suspension preheater, now a reductionchamber 100', the cyclone melter 200 and plasma torches 600a-c forproviding an enthalpy boost and additional high temperature reducing gasto the process heater. The slagging cyclone gasifier 400 removesnormally 70% of the coal ash introduced into the cyclone gasifier,thereby reducing the amount of slag removal required in the metal makingstages of the process. Nominal exit temperatures from the gasifier arein the range of 2800° F-3500° F, with stoichiometries typically lessthan 60%. The materials to be reduced are introduced into the interfaceassembly 500 which connects the gasifier 400 and reduction chamber 100'assemblies, thereby decreasing the reducing gas temperature. Thegas-solids suspension 404 then enters the well-stirred/plug flowreduction chamber 100' where additional high temperature reducing gasesare injected through plasma torches 600b-600c, thereby providingadditional enthalpy to the gases and mineral matter contained within thepreheater assembly. Preferred reducing gases are hydrogen and carbonmonoxide, which can be obtained from the reforming of natural gas.

The average temperature of the gas-solids suspension exiting thepreheater assembly is governed by the types of materials being reduced.For iron making applications, the exit temperature of the gas-solidssuspension from the preheater assembly is typically greater than 2800°F. The preheated mineral matter then enters the cyclone melter 200,where separation and deposition of the particulate matter occurs alongthe melter walls 202.

To achieve high levels of reduction, it is advantageous to introduce apulverized solid carbon source such as coke or coal into either theinterface assembly 500 along with th mineral matter or separately intothe reduction chamber 100'. The interaction of the solid carbon with theliquid mineral matter results in high levels of metal oxide reduction.For iron reduction, the reaction involved can be represented as follows:

    FeO+C=Fe+CO: ΔH=+37084 cal/mole.

Because carbon monoxide is one of the reaction products, it is generallyaccepted that the reduction of iron oxides by carbon proceeds indirectlyby carbon monoxide and that the carbon dioxide formed then reacts withthe carbon to reform carbon monoxide as follows:

    FeO+CO=Fe+CO.sub.2 :ΔH=-4136 cal/mole

    C+CO.sub.2 =2CO:ΔH=+41220 cal/mole

Because the gasification of carbon by CO₂ is highly endothermic and alsorequires a high temperature to proceed at an acceptable rate, theoverall reduction rate is controlled by the rate of gasification ofcarbon. The rate of gasification of carbon will depend on the reactivityof the carbon, the temperature, and the availability of heat to maintainthe reaction. Therefore, the rate of reduction by solid carbonultimately depends on the rate of heat transfer from the heat source tothe reacting materials. In the present invention the use of fineparticles heated in suspension and the convective mixing of the liquidlayer formed in the cyclone melter serves to enhance the rate of theoverall reduction process.

To achieve effective levels of metal oxide reduction, it is known thatthe reducing gas ratio (RGR) which is defined as:

    RGR=(CO+H.sub.2)/(CO+CO.sub.2 +H.sub.2 +H.sub.2 O)

should be at least 0.6 or greater.

As stated previously, the primary components of these embodimentsinclude a slagging cyclone gasifier 400; a gasifier/preheater interface500 connecting the gasifier 400 to a preheater/reduction chamber 100'; acyclone melting chamber 200 at the exit end of the reduction chamber100'; a cyclone exit assembly 300 at the exit of the cyclone meltingchamber 200; and one or several auxiliary gas heating assemblies, oneassembly 600a being connected to the interface 500 and the otherassemblies 600b and 600c being connected to the reduction chamber 100'.

The preheater/reduction melter chamber 100' is essentially the same asthe preheater 100, however, the refractory linings of the chamber 100'will have to be different to survive the strong reducing conditionswhich will exist therein.

The slagging cyclone gasifier 400 produces a hot reducing gas 403 whichbecomes the primary reductant for the pulverized ore or metal-containingwaste introduced into the reduction chamber 100'. Ore-containing mineralmatter 15 and additional reducing agents 50, such as pulverized coal,pulverized coke, liquid hydrocarbon fuels or gaseous hydrocarbon fuels,are introduced through inlets 502, 504 into the interface assembly 500.

Because it is oftentimes advantageous to elevate the temperature of thegas-solid suspension 404 exiting the interface 500 into the upper region108 of the reducing chamber 100', as shown in FIGS. 10-12, plasmatorches 600b, 600c are provided to heat reducing gases which areinjected through inlets 606b, 606c attached to the reduction chamber100'. These plasma torches can be used to obtain the desired hightemperatures (in the range of 3,000° F) within the chamber 100'. Tomaintain the highly reducing condition in the reducing chamber, it isnot desirable to introduce additional oxidizing materials into thechamber 100' as provided in the previous embodiments; however, theintroduction of additional reducing agents is permitted and desirable.These additional reducing agents can be introduced and heated, by meansof the plasma torches 600b, 600c or by other heating means andintroduced into the reducing chamber through the inlets 606b, 606c. Thefunction of these inlets is similar to the functioning of the inlets106a, 106b into the combustion chamber in the embodiment shown in FIGS.1 and 2; that is, to produce a region within the chamber 100' where thesuspended liquid-solid material and/or other reducing agent such as cokeor coal particles are correctively heated by the gases in the preheater.A typical configuration of the reducing chamber/ preheater 100' is acounter-rotating vortex reactor as shown in FIG. 11. In such a reactorit is possible to control the mixing within the upper region 108 of thechamber 100' by adjusting the mass flow and inlet velocities into there:as previously described in conjunction with the preheater 100.

An alternate configuration of the reducing chamber 100' is the opposedjet design shown in FIG. 10 wherein the heated reducing gases from theplasma torches 600b, 600c are injected upwardly toward each other intothe upper region 108 of the chamber 100' so that the gases impingepreferably at a 45° angle and produce the well-mixed conditions in theupper region 108. While 45° is the preferred angle of inclination of theplasma torches 600b, 600c, the angle may be within the range of 30°-60°.The configuration is similar to that discussed with respect to FIG. 4.

Preferred reducing gases to be heated by the auxiliary heat sources600a, 600b, and 600c include hydrogen, carbon monoxide, natural gas orvarious mixtures thereof. Natural gas can be used as fuel and as areducing gas. The disadvantage of using natural gas directly as areducing gas with a plasma torch, however, relates to soot formationwhich can occur through the cracking of CH₄. Mixtures of hydrogen andcarbon monoxide do not have this problem. If the time-temperaturerequirements dictate, additional mineral matter can be injected throughduct 114 adjacent the exit end 118 of the chamber 100'. Additionalreducing agents 50 may also be added to the suspension within thechamber 100' at the same time the additional mineral matter is injectedthrough inlet 114 into the preheater. A preheated gassolids suspension116 composed of the suspended mineral matter and the heated reducinggases exits the chamber 100' into the cyclone melting chamber 200 bymeans of a suitable inlet duct assembly 204. As with the previousembodiments of the invention discussed herein, the preheated mineralmatter, is separated, dispersed and mixed along the cyclone melter walls202 where melting of the mineral matter occurs.

To reach high levels of reduction, it may be necessary to provide solidcarbon in physical contact with the melted mineral matter within thecyclone melting chamber during the melting process to effectliquid-solid reduction reactions. In order to make sure the solid carbonmaterial is available in the cyclone melting chamber 200 , thetime-temperature histories of the pulverized carbon containing materialsintroduced into the preheater can be controlled as previously described.Preferred alternative locations for the introduction of the solidreducing agents 52 are the interface assembly 500 at inlets 502, 504,the head end of the reduction chamber 100' at inlet 122 and near theexit of the chamber 100' at inlet 114.

Without further elaboration, the foregoing will so fully illustrate myinvention that others may, by applying future knowledge, adopt the samefor use under various conditions of service.

What I claim as my invention is:
 1. An apparatus for producing glassfrom glass batch materials, in the presence of a fuel and oxidant, saidapparatus comprising:cyclone glass melt reactor means for forming aliquid glass melt; combustion preheater means for receiving said glassbatch materials, fuel and oxidant and combusting said fuel and oxidanttherein and heating said glass bat h materials to a temperature at leastequal to the melt temperature of said glass batch materials, saidcombustion preheater means having an outlet connected to said cycloneglass melt reactor means; and inlet means for injecting said oxidantinto said combustion preheater means and creating a counter rotatingwell-stirred region within said combustion preheater means.
 2. Anapparatus as claimed in claim 1, wherein said combustion preheater meansis comprised of a cylindrical, vertically positioned chamber defined bya cylindrical wall and having upper and lower ends and a longitudinalaxis therethrough, wherein said inlet means is positioned at said upperend so as to create said well-stirred region at said upper end.
 3. Anapparatus as claimed in claim 2, wherein said combustion preheater meansfurther comprises a converging chamber section converging downward fromsaid cylindrical chamber to said outlet, and being connected to saidcyclone glass melt reactor means at said outlet.
 4. An apparatus asclaimed in claim 2, wherein said inlet means is positioned tangentiallyto said wall of said cylindrical chamber.
 5. An apparatus as claimed inclaim 4, wherein said inlet means comprises at least two verticallyspaced inlet ports directed into said upper end of said verticalcylindrical chamber.
 6. An apparatus as claimed in claim 5, wherein saidinlet ports are vertically spaced apart a distance equivalent to 174 ofthe diameter of the cylindrical chamber to 1 diameter of the cylindricalchamber.
 7. An apparatus as claimed in claim 2, further comprisingauxiliary heat means connected to said cylindrical chamber forintroducing a heated transfer gas into said cylindrical chamber.
 8. Anapparatus as claimed in claim 7, wherein said auxiliary heat means isconnected to said chamber coaxially with said longitudinal axis of saidchamber.
 9. An apparatus as claimed in claim 7, wherein said auxiliaryheat means comprises a plasma generator.
 10. An apparatus as claimed inclaim 9, wherein said plasma generator is a non-transferred plasmagenerator.
 11. An apparatus as claimed din claim 1, furthercomprising:fuel injection means connected to said preheater means forinjecting said fuel into said preheater means; and glass batch supplymeans connected to said preheater means for introducing said glass batchmaterials into said preheater means.
 12. An apparatus as claimed inclaim 1, further comprising fuel injection means connected to saidcombustion preheater means for injecting said fuel into said combustionpreheater means.
 13. An apparatus as claimed in claim 12, wherein saidfuel injection means is comprises of:a gasifier having at least oneinlet thereinto and an exit therefrom; and interface means at said exitconnecting said gasifier and said combustion preheater means.
 14. Anapparatus as claimed in claim 13, wherein said gasifier comprises acylindrical chamber having a slag trap and said at least one inletcomprises a fuel inlet and an oxidizing material inlet.
 15. An apparatusas claimed in claim 14, wherein said oxidizing material inlet istangential to the circumference of said cylindrical chamber.
 16. Anapparatus as claimed in claim 13, further comprising glass batch supplymeans connected to said interface means for introducing glass batchmaterial into said interface means.
 17. An apparatus as claimed in claim13 wherein said interface means is comprises of:a chamber having acircumference therearound and a first inlet thereinto connected to saidexist of said gasifier; and exit duct means connected to said combustionpreheater means for delivering the contents of said chamber into saidcombustion preheater means.
 18. An apparatus as claimed in claim 17,wherein said first inlet into said chamber of said interface means iscoincident with said exist duct means.
 19. An apparatus as claimed inclaim 17, further comprising auxiliary heat means connected to saidinterface means for introducing a heated transfer gas into saidinterface means.
 20. An apparatus as claimed in claim 19, wherein saidauxiliary heat means is connected tangentially to the circumference ofsaid chamber of said interface means.
 21. An apparatus as claimed inclaim 19, wherein said auxiliary heat means comprises a plasmagenerator.
 22. An apparatus as claimed in claim 21, wherein said plasmagenerator is a non-transferred plasma generator.
 23. A method oftreating materials for delivery to a cyclone melter having an inlet andan outlet, said method comprising the steps of:connecting asuspension-type cylindrical combustion preheater to the inlet of saidmelter, said preheater having a vertically oriented longitudinal axisand an upper and a lower end, introducing a first material into saidpreheater; introducing a fuel into said preheater; and introducing apreheated oxidant into said preheater so as to create a counterrotating, turbulent mixture of said fuel, said oxidant and said firstmaterial within the upper end of said preheater, whereby a well-stirredregion of said oxidant, said first material and said fuel is created inthe upper end of said preheater.
 24. A method as claimed in claim 23,wherein said first material and said fuel are introduced into saidpreheater coaxially with said longitudinal axis of said preheater.
 25. Amethod as claimed in claim 23, wherein said step of introducing saidpreheated oxidant into said preheater comprises tangentially introducingsaid oxidant into said upper end of said preheater.
 26. A method asclaimed in claim 25, wherein said step of introducing said preheatedoxidant into said preheater comprises tangentially introducing saidoxidant into said upper end of said preheater at at least two differentlocations along the longitudinal length of said preheater in order toproduce said counter rotating, turbulent mixture.
 27. A method asclaimed in claim 23, further comprising combusting said fuel and saidoxidant within said upper end of said preheater.
 28. A method as claimedin claim 27, wherein said combustion is initiated by igniting said fueland said oxidant within said upper end.
 29. A method as claimed in claim23, wherein:said fuel is a slurry fuel; and said step of introducingsaid fuel into said preheater comprises injecting said slurry fuelthrough an injection/atomizer assembly into said preheater.
 30. A methodas claimed in claim 23, wherein said step of introducing said oxidantinto said preheater comprises adjusting the mass flow and velocity ofsaid oxidant into said preheater.
 31. A method as claimed in claim 30,wherein said preheater has an oxidant inlet thereinto and adjusting themass flow and velocity of said oxidant is done by adjusting the oxidantinlet dimensions into said preheater.
 32. A method as claimed in claim31, wherein said adjusting of said inlet dimensions is done by controlvalves.
 33. A method as claimed in claim 23, further comprisingcontrolling the time-temperature history of said first materialintroduced into said preheater by adjusting the location of introductionof said first material into said preheater, by adjusting the directionof introduction of said first material into said preheater, by adjustingthe velocity of said first material at the point of introduction intosaid preheater and by adjusting the particle size distribution of saidfirst material.
 34. A method as claimed in claim 23, further comprisingintroducing said first material along with said oxidant.
 35. A method asclaimed in claim 23, further comprising injecting a second material intosaid preheater in the lower end thereof adjacent said inlet of saidmelter, said second material having a melting point lower than saidfirst material.
 36. A method as claimed in claim 23, further comprisingadjusting the temperature within said preheater.
 37. A method as claimedin claim 36, wherein said step of adjusting the temperature within saidpreheater comprises performing at least one of the followingsteps:adjusting the combustion stoichiometry within the preheater; andadjusting the type of fuel used.
 38. A method as claimed in claim 36,wherein said step of adjusting the temperature within said preheatercomprises providing auxiliary heat from an auxiliary heat source intosaid preheater.
 39. A method as claimed in claim 38, wherein said stepof providing auxiliary heat into said preheater comprises:connecting aplasma generator to said upper region of said preheater; and passing atransfer gas through said plasma generator and injecting said transfergas passing through said plasma generator into said preheater.
 40. Amethod as claimed in claim 39, wherein said transfer gas is selectedfrom the group consisting of air, fuel gas an inert gas.
 41. A method asclaimed in claim 23, further comprising providing a gasifier forgasifying said fuel prior to injecting said fuel into said preheater.42. A method as claimed in claim 41, wherein said fuel comprises anash-producing fuel, and a preheated combustion oxidant is injected intosaid gasifier for gasifying said ash-producing fuel.
 43. A method asclaimed in claim 42, wherein said combustion oxidant is injectedtangentially into said gasifier to cause a strong swirling motion withinsaid gasifier, whereby fuel ash from said ash-producing fuel isseparated to the walls of said gasifier in the form of molten slag. 44.A method as claimed in claim 43, further comprising removing said moltenslag from said gasifier.
 45. A method as claimed in claim 41, furthercomprising:connecting an interface means between said preheater and saidgasifier; introducing said fuel from said gasifier and said firstmaterial into said interface means; and thereafter, injecting said fueland first material from said interface means into said preheater.
 46. Amethod as claimed in claim 45, further comprising providing a plasmagenerator and attaching said plasma generator to said interface means.47. A method as claimed in claim 46, further comprising passing atransfer gas through said plasma generator and into said interface meansin order to add a heat boost to said preheater.
 48. A method as claimedin claim 23, wherein said first material comprises glass batchmaterials.
 49. A method as claimed in claim 23, wherein said firstmaterial is a material selected from the group consisting of pulverizedfrit, pulverized cullet, fly ash and toxic waste.
 50. A method asclaimed in claim 23, wherein said well-stirred region has a length todiameter ratio of 0.5:1-1.5:1.
 51. A method as claimed in claim 23,wherein the preheater further includes a plug-flow region beneath saidwell-stirred region, said plug-flow region being located in the lowerend of said preheater and having length to diameter ratio of0.5:1-1.5:1.
 52. An apparatus for processing materials under oxidizingconditions, said apparatus comprising:combustion preheating means forreceiving at least a first material, fuel and oxidant and treating saidfirst material under oxidizing conditions, said preheating means havingan inlet and an outlet; oxidant inlet means connected to said preheatingmeans for injecting said oxidant into said combustion preheating meansin a counter rotating manner and creating a well-stirred region withinsaid preheating means; cyclone melter means for receiving treated firstmaterial from said combustion preheating means and for separating anddepositing said treated first material onto the wall thereof; and meansconnected to said combustion preheating means for introducing said firstmaterial to be processed into said combustion preheating means.